The invention pertains to the field of systems for automatically performing blood typing operations, and, more particularly, to systems for controlling automated liquid handling apparatus to do blood typing and for interpreting the results from a plate reader and for managing the data generated by the liquid handling apparatus and the plate reader apparatus and for printing various reports.
Modern blood banks must perform thousands of blood typing and antibody screening operations and manage the data resulting from such tests. These operations involve the handling of thousands of samples of donor blood, the pipetting of reagents into samples of the plasma and red blood cells from the donor blood and the optical reading of the wells containing the donor samples and the reagents to determining the pattern of positive and negative responses to various reagents. The pattern of positive and negative responses constitutes a template which characterize the blood as being from a particular blood group and having a particular Rh factor. Each test of each donor's blood involves pipetting of multiple samples of that donor's plasmas into multiple wells and pipetting of multiple samples of diluted red blood cell samples into multiple wells. Multiple diluted reagents are then added to the multiple wells containing plasma and red blood samples and various reactions either occur or do not occur depending upon the blood type and the reagent in each well. Typically, these reactions manifest themselves as clumps of protein in the bottom of the well for a positive reaction and no clumps for negative reactions, the pattern of positive and negative reactions determines the blood type.
The blood type can be determined by placing the multiple wells under a strong light source and reading the optical absorbence, i.e., the amount of light which gets through the bottom center of the well. Typically absorbance readings are taken on both sides of the center, bottom of each well, and the results are compared to certain threshold criteria for absorbance. The comparison of the readings will indicate the presence of a clump at the bottom of the well (low absorbance in the off center readings) and therefore a positive reaction or the absence of a clump and therefore a negative reaction (high absorbance on both off center readings).
Clearly, the process of blood typing of thousands of donor samples involves many thousands of liquid handling steps and the generation of many thousands of absorbance readings for the multiple wells devoted to each donor. Further liquid handling steps are involved in automated antibody screening, and some special tests may have to be done by hand on the blood which are not subject to automated liquid handling. Test results from these antibody screen tests and other tests done by hand must be recorded for each donor's blood for which these tests are done. Further, testing procedures for blood typing can change over time in that different dilution values are often needed for different batches of reagents to get the proper absorbance readings. Further, the amount of dilution of the red blood cells should be optimized. The data for the optimal dilution values must be recorded.
Further, other process parameters of the blood typing sequence should be subject to customization to enable the various users to customize their testing procedures to conform to local practice. This data defining the characteristics of each step, such as the amount of each sample to be placed in each well, which wells in which to place samples, the amount of dilution in certain steps, the wells to place reagents in, the number of mixes at various points in the process and various other criteria, should be subject to customization, should be easily changeable, and should be remembered by some mechanism so that it can be automatically invoked each time a procedure is performed without having to look it up every time. Of particular importance is the amount of dilution of each particular reagent which should be used to optimize the absorbance for that reagent and to conserve the amount of reagent used. These reagents are often quite expensive.
Further, it is useful to have a quality control and accountability system such the quality of data generated in the testing is consistently high and the persons performing the testing can be determined. For example, it is useful to know the expiration data for all the reagents in stock and the associated absorbance values for each reagent lot over the period of its usage. It is also useful to compare the test results for known sample types to the results that should have been obtained as a check on the accuracy of the system. It is also useful to be able to generate reports on daily or monthly activities to determine the amount of certain types of blood in stock and where it can be found. The number of "no type determined" test outcomes (hereafter NTD).
Thus, a large amount of data in the form of process controlling parameters and test results are involved in blood typing and antibody screening operations, and a large amount of record keeping for this data is involved. Therefore a need has arisen for a system which can perform these thousands of liquid handling steps reliably and tirelessly and which can handle the thousands of data records which characterize the liquid handling and which constitute the data record for each donor. Further, such a system should be access controlled and implement accountability. It should also ease quality control operations and maintain data useful in quality control efforts. Such a machine should also maintain all test results and be able to communicate them to a mainframe computer for permanent storage or allow them to be archived onto permanent magnetic storage. Such a machine should also enable the automated generation of reports for management.